Subtractive color photography



Patented Mar.l 7, 1944 SUBTRACTIVE CLOR. PHOTOGRAPHY Wilhelm Schneider,Dessau, Germany, assignor to General Aniline & Film Corporation, New

York, N. Y., a corporation of Delaware Application september 1o, 1940.serial No. 356,143

. In Germany April 27, 1937 comms. (cies-2) f I I,

My present invention relates to an improved light-sensitive element forcolor photography. This application is a continuation-impart of myapplication Ser. No. 199,349, filed April 1, 1938.

In the known subtractive processes for producing multicolor picturesmultilayer exposure material is used in which the individual layers aresensitized for diierent regions of the spectrum. In order to obtain thebest possible utilization of the light the sensitizing of the sev- 1oeral layers is so chosen that the region of sensitivity of the severallayers taken together isv equal to and even exceeds the total range ofthe visible spectrum. In order to attain'the best possible colorseparation the sensitizing dyeiii stuffsY are so selected that theirsensitizing curves show a somewhat steep descent towards the long waveregion. The maxima of the sensitizin'g range for the individual layers,in conformity with the sensitizing of the emulsion layers or theadditive exposure process, lie in the middle oi the three main regionsof the visible spectrum, namely at about` 450 ma, about 550 my. andabout 650 ma. In this respect reference may be made,

for example, to the exposure material described a5 in U. S. Patent No.2,059,884, page 2,left column. lines 1l to 36, in which thegreen-sensitive layer is sensitized for the region of 510 to 590 my.with a. maximum at about 550 ma and the red-sensitive layer issensitized for the region of 600 tov 700 ma with a maximum at about 6,50ma. Thus it was generally supposed in the art that for `thered-sensitive layer a sensitization must be selected which embraces asfar as possible the total red portion of the spectrum. Present daycommercial photographic materials for subtractive multicolor photographsare therefore sensitized in this manner. With such a material there isattained a very good reproduction ofi color, if the time of exposure iscorrectly selected. However, under changing weather conditions verydifferent results may be obtained, in particular infoggy and rainyweather the pictures may easily be bluish, whereas in cloudy but clearweather reddish pictures are obtained.l

Further objects of the invention will become Il apparent from thefollowing detailed descrip tion.

Reference is made to the accompanying drawing', thel figures of-whichshow diagrammatically and in an exaggerated scale light sensitiveelements according to the invention. The figures are self-explanatory.-

This inventionv is vbased on the observation that the aforementioneddisadvantages are avoidedin a. multilayer photographic material thered-'sensitive layer of which has a sensitizing range of from about 500to about 670 ma with 'a sensitizing maximum of about 580 to'aboutv 63()ma. The following is an especially suitable material: The blue-sensitivelayer has a sensitive range of about 400 ma to about 480 ma with amaximum at about 430 ma to about 460 ma, the green-sensitive layer has asensitized region from about 460 mp. to about 610 ma with a maximum atabout 540 mp. to'about 555 mu and the red-sensitive layer a sensitizedregion of about 500 mp. to about 670 ma with a maximum at about 580 mato about 630 ma.' This photographic material is of special advantagewhen used together with an ultra-violet absorbing filter, Preferablythis ultra-violet iilter is used in the form of'a illter layer on thephotographic material. Such material shows when compared with the knownmaterial the advantage that a correct color reproduction is securedunder varied conditions of weather. With this material; therefore, thevarying content of ini fra-red and ultra-violet light in the daylight iswithout iniluence.

This material does not only exclude the inuence of thejweatherconditions, but the color reproduction is also. improved in otherrespects. Thus certain blue tints, for example ot flowers and fabricswhich f hitherto have reproduced in too red a color, are reproducedcorrectly. It is al further advantage that it is possible to vobtain asoft gradation of the emulsion bya sensitization characterized byoverlapping spectral ranges according-to the presentimencqlor It will beapparent from the above disclosure that the most important feature ofthe invention is the special sensitizing of the layers. The colorpicture may Be produced in the multilayer material in various ways.Especially serviceable are layers as described in U. S. lpatentapplica-.

The following examples illustrate the invention.

Example I `A support A (Figure 1) is coated with a silver An emulsionlayer I sensitized with 1,1'diethhalide gelatin emulsion layer Ipanchromatic sensitized with1,1'-diethyl-5,6dimethoxy-5-diethylamino-benzthia-carbocyanine iodideand containing decyl g 1 oxy 2 naphthoylamine as blue-green colorforming component. 'I'he next emulsion layer ,H immediately superposedthereon is orthochromatic sensitized with 1,1diethyl 5,6dimethylbenzthio naphthoxo mesomethyl-carbocyanine iodide. Said layercontains 1 (m stearyl aminophenyl) 3 methyl 5- pyrazolone as colorforming component for the purple image. The last named layer issuperposed by an intermediate illter layer III containing a yellowdyestui! which is capable of being washed out or bleached out. Finallythe filter layer III is superposed by an unsensitized, i. e., bluesensitive emulsion'layer IV containingdecanoylaminq-benzoyl-acetic-acid-p-anisidide.

Example I! In a multicolor 111m according to Example `I containing thesame color forming components Example III A multicolor materialaccording to Figure 2 is builtup as follows:

A support A. A panchromatic emulsion layer I sensitized with1,1diethyl-5,5'-diethylaminobenzoxo-carbocyanine-perchlorate containing-a condensation product of a compound obtained by condensing a mixedpolymerisate of vinylchloride and the anhydride of maleic acid with-1,5-aminonaphthole as blue-green color component. An emulsion layer IIsensitizedwith 1,1'diethyl ,B-naphthoxo-mesomethylcarbocyanine bromidecontaining a condensation product of a compound obtainegl by condensinga mixed polymerisate of vinylchloride and the anhydride of maleic acidwith paminophenylmethylpyrazolone as purple component. The layer I isseparated rom layer II by a thin gelatin layer G. A ilter layer IIIcontaining a yellow dyestuff which is capable of being washed out or'bleached out. An unsensitized blue-sensitive emulsion layer IVcontaining the condensation product of a compound obtained by condensingthe malonlc monochloride and octylamine with aniline as color formingcomponent for the yellow image.

Example IV A multicolor material according to Figure 1 is built up asfollows:

yl 5,6,5,6' tetramethyl benzseleno carbocyanine iodide containingl-abietylamino--oxynaphthalene-G-carboxylic acid. A layer II sensitizedwith 1,1diethyl-6-methoxy-benzseleno- 6'-methoxy-quinopseudocyanineiodide containing 3 abietylamino -5'- sulfo 1 phenyl 3-methyl-5-pyrazolone. A yellow lter layer III. An unsensitized bluesensitive emulsion layer IV containingp-abietylamino-benzoyl-acetic-acid- `anilidepcarboxylic acid.

Example V In a multicolor material according to Example IV- containingthe same color forming components the emulsion layers 'are sensitizedasiollows:

Layer I: 1,1'-diethyl5,5'disulfoethyl6,6-dimethoxy-benzthio-carbocyaninebromide.

Layer II: `1,1'diethyl-benzseleno-isocyanine iodide. i

y Example VI A multicolor material according to Figure 3 is built up inthe following manner: i

A panchromatic emulsion layer I sensitized aceording to Example Icontaining 1Nstearyl4 N (1' oxy 2' naphthoyl)phenylene-dfamine-sodiumsulfate. An orthochromatic emulsion layer IIsensitized accordingto Example I containing 1-(3sulfophenyl) 3 (4"stearylaminophenyl) -5-pyrazolone. A yellow lter layer III. Anunsensitized blue-sensitlve'emulslon layer IV containingm-stearyl-amino-benzoylacetanilide-p-carboxylic acid. A thin gelatinlllter layer V transparent to light but absorbing the ultra-violet rayscontaining m-aminobenzoyl-diamino-stilbensodiumdisulfonate or otherusual substances which absorb the invisible short waves of the spectrumand may contain groups capable of rendering the lter substance fast todiffusion.

What I claim is:

1. A light-sensitive element for color photography comprising a`support, a blue-sensitive silver halide emulsion layer having asensitive range from about 400 to about 480 ma with a maximum at about430 ma to about 460 ma, a green-sensitive silver halide emulsion layerhaving a sensitized region from about 460 mp. to about 610 ma with amaximum Aat 540 mp. to about 555 ma, and a red-sensitive silver halideemulsion layer having a sensitized region from about 500 ma to about 670ma with a maximum at about 580 ma to about 630 ma.

2. A light-sensitive element for color photography comprising a support,a blue-sensitive silver halide emulsion layer having a sensitive rangefrom about 400 to about 480 ma with a maximum at about 436 my. to about460 ma, a green-sensitive silver halide emulsion .layer having asensitized region from about 460ml to about 610 my. with a maximum at540 ma to about 555 mp., and a red-sensitive silver halide emulsionlayer having a sensitizedregion from about 500 ma to about 670 ma with amaximum at about 580 ma to about 630 ma. said silver halide emulsionlayers containing color formers fast to diifusion.

3. The light-sensitive element defined in claim 1, in' which anultra-violet absorbing lter layer 4 is arranged in front of theblue-sensitive emul-

